Improving the performance of cutting fluids by using ZnO and ZrO2 nanoparticles

Sustainability is nowadays a global research priority, especially in machining, where optimizing production processes for increased productivity, profits, and efficiency is key. Addressing this need, the adoption of nanofluids in minimum quantity lubrication machining has surged, aligning with environmental concerns and regulatory demands. In this study, sustainable zinc oxide (ZnO) and zirconium dioxide (ZrO 2 ) nanoparticles fabricated using plant extracts have been incorporated into conventional cutting fluids to enhance their machinability performance under minimum quantity lubrication for turning process. The microstructural analysis confirms the successful synthesis of the targeted nanoparticles with excellent purity and size distribution. The addition of nanoparticles significantly enhanced thermal conductivity from 0.5916 W/(m⋅K) for the base fluid to 0.6286 W/(m⋅K) for ZnO and to 0.6242 W/(m⋅K) for ZrO 2 . Further, nanofluids exhibited an increased dynamic viscosity, 1.435 mPa.s for ZrO 2 and 1.125 mPa.s for ZnO as compare to 0.7644 mPa.s of base fluid, attributed to the nanoparticle confinement effect whereas contact angle measurements indicated an improved wettability for all nanofluids. Machining experiments validate the efficacy of nanofluids, demonstrating reduced cutting temperatures and enhanced surface finish. Notably, ZrO 2 -based nanofluids exhibit improved tribological response, while ZnO-based nanofluids showcase exceptional heat transfer ability, offering promising solutions to key technical challenges in machining processes. In conclusion, this study underscores the potential of green, sustainable ZnO and ZrO 2 nanoparticles as additives in cutting fluids, poised to revolutionize metalworking and manufacturing processes, thereby enhancing product quality and sustainability.